US5444203A - Safety switch for an industrial machine - Google Patents

Safety switch for an industrial machine Download PDF

Info

Publication number
US5444203A
US5444203A US08/211,866 US21186694A US5444203A US 5444203 A US5444203 A US 5444203A US 21186694 A US21186694 A US 21186694A US 5444203 A US5444203 A US 5444203A
Authority
US
United States
Prior art keywords
operating member
contact device
pressure
lever arm
safety switch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/211,866
Other languages
English (en)
Inventor
Sven-Eric Gunnarsson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB AB
Original Assignee
Asea Brown Boveri AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Asea Brown Boveri AB filed Critical Asea Brown Boveri AB
Assigned to ASEA BROWN BOVERI AB reassignment ASEA BROWN BOVERI AB ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: GUNNARSSON, SVEN-ERIC
Application granted granted Critical
Publication of US5444203A publication Critical patent/US5444203A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
    • F16P3/00—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
    • B25J19/06—Safety devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/50—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a single operating member
    • H01H13/506—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a single operating member with a make-break action in a single operation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H3/00—Mechanisms for operating contacts
    • H01H3/02—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch
    • H01H3/022—Emergency operating parts, e.g. for stop-switch in dangerous conditions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2300/00—Orthogonal indexing scheme relating to electric switches, relays, selectors or emergency protective devices covered by H01H
    • H01H2300/026—Application dead man switch: power must be interrupted on release of operating member
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2300/00—Orthogonal indexing scheme relating to electric switches, relays, selectors or emergency protective devices covered by H01H
    • H01H2300/028—Application dead man switch, i.e. power being interrupted by panic reaction of operator, e.g. further pressing down push button

Definitions

  • the present invention relates to a hand-operated safety switch for an industrial machine, intended to be connected with an emergency stop circuit for the machine.
  • the safety switch is primarily intended to be used in applications in the engineering industry, for example in an industrial robot application where persons are present within the operating range of the robot.
  • An industrial robot can be controlled with the aid of a joystick.
  • the position and/or orientation of the robot tool can be controlled in the desired manner by means of the joystick.
  • the joystick can either be arranged on a fixed control cabinet or on a smaller, separate programming unit, which during programming or teaching can be held in the hand or be placed on a table. In order that programming shall not take an unreasonably long time, it is necessary that a full deflection of the joystick causes a movement with a relatively high speed of response in the robot.
  • a safety plate is arranged on programming units of the above-mentioned kind, on which safety plate the operator's hand rests when operating the joystick with the aid of the fingers.
  • the safety plate senses this and influences the control system such that the joystick is rendered inoperative. In this way, it is prevented that an unintentional contact with the joystick gives rise to a movement of the robot.
  • a device of this kind is described in Swedish printed patent application 450 285 and in Asea Journal 1982, No. 6, pp. 145-150.
  • the present invention aims to provide a safety switch designed for the above-mentioned field of use, which does not suffer from the above-mentioned drawbacks of comparable prior art designs. This is achieved according to the invention by a safety switch with the characteristic features stated in the claims.
  • the safety switch comprises a contact device with a hand-operated device in which a pressure operating member is displaceable against the action of a return spring from a first end position via an operating position to a seconded end position, whereby the safety circuit, into which the switch is intended to be connected, is connected only in the operating position.
  • the operating device is arranged such that the contact device is not affected during the return movement of the pressure operating device from its second to its first end position, and thus the safety circuit remains open during the whole of this return movement.
  • a safety switch according to the invention makes it possible for industrial machines of the above-mentioned kind to be installed, used and maintained with an adequate degree of safety against personal injury.
  • the switch is simple to manufacture and mount.
  • FIG. 1 is a side view of a safety switch according to the invention in its initial position (first end position),
  • FIG. 2 shows the switch in the same position in a view from above
  • FIGS. 3 and 4 are side views of the switch in its operating position (mid-position) and in its second end position, respectively,
  • FIGS. 5, 6 and 7 show the housing of the switch in a view from the side (FIG. 5), in an end view from the left (FIG. 6), and in a view from above (FIG. 7), respectively,
  • FIGS. 8 and 9 show a pressure rod, included in the operating member of the switch, in a side view and in an end view from the left, respectively, and
  • FIGS. 10 and 11 show a lever arm, included in the switch, in a side view and a view from the left, respectively.
  • the safety switch shown in FIG. 1 comprises a housing 1, in the upper part of which a microswitch 2 is fixed and in the lower part of which an operating member 3 in the form of a pressure rod 31 with a pressure plate 32 is journalled so as to be longitudinally displaceable. Between the pressure plate 32 and the housing 1, a compression spring (return spring) 33 is arranged.
  • the microswitch 2 comprises at least one contact pair with one fixed and one movable contact 21 and 22, respectively. With the aid of an actuating member 23, the movable contact 22 may be displaced from the open position shown in FIG. 1 to the closed position shown in FIG. 3.
  • the movable contact is permanently influenced by a return spring 24 in a direction towards the open position.
  • the transmission of the operating force from the operating member 3 to the microswitch 2 is achieved by a lever arm 4 which, with the aid of a cylindrical pin 41, is rotatably journalled in the housing 1.
  • a compression spring 42 In the lower part of the lever arm 4 there are a compression spring 42 and a ball 43.
  • the spring-loaded ball 43 presses against the pressure rod 31, which is provided with a recess 36 (FIG. 4), arranged at that end of the rod which is located furthest away from the pressure plate 32 and cooperating with the ball 43, for achieving a coupling engagement between the pressure rod and the lever arm.
  • the upper end portion of the lever arm makes contact with the actuating member 23 of the microswitch.
  • the housing 1 of the safety switch is provided, in its upper part, with a fixing hole 11 for the microswitch 2 and, in its lower part, with a bearing hole 12 with guide slots 13 for the pressure rod 31.
  • the center lines of the holes 11, 12 are parallel.
  • two parallel wall portions 14, 15 extend, between which the lever arm 4 is intended to be mounted.
  • the wall portions are provided with through-holes 16 for the bearing pin 41 of the lever arm.
  • the housing 1 is provided with two fixing holes 17 for fixing the safety switch in, for example, a programming box for an industrial robot.
  • the pressure rod 31 which is shown separately in FIGS. 8 and 9, has a substantially circular cross section and is provided at one end with an axial hole 34 for fixing the pressure plate 32. At its other end the pressure rod is provided with a recess which, nearest the end surface of the rod, is made with a deeper portion 36 which forms a seat for the ball 43 and which, via a shoulder 37, changes into a shallower portion 38 which forms a rolling or sliding path for the ball 43.
  • the height of the shoulder is considerably smaller than the diameter of the ball, for example about 1 mm if the diameter of the ball is 4 mm.
  • the shoulder can suitably be made inclined so as to obtain a more even transition between the two portions 36 and 38. In the embodiment shown the shoulder 37 forms an angle of about 45° with the longitudinal axis of the pressure rod.
  • the pressure rod 31 is provided with radially projecting guide pins 39 which fit into the guide slot 13 of the housing.
  • the pins 39 limit the axial movement of the pressure rod in a direction towards the right to the end position shown in FIG. 1 and also prevents the rod from moving in the direction of rotation.
  • the lever arm 4 is shown separately in FIGS. 10 and 11. It has a transversal hole 44 for the bearing pin 41 as well as a longitudinal hole 45 for accomodating the compression spring 42 and the ball 43.
  • the centre lines of the holes 44, 45 are directed perpendicularly to each other.
  • the pressure rod 31 is suitably made of a plastic material, for example acetal plastic, whereas the other parts, such as the housing 1 and the lever arm 4, are suitably made of metal.
  • the safety switch operates as follows: In the initial position shown in FIG. 1, the spring 33 keeps the pressure rod 31 in its first end position, and the spring 24 built into the microswitch keeps the switch in the open position, whereby the safety loop into which the switch is connected is open. By pressing on the pressure plate 32, the pressure rod 31 is pressed in and influences the lever arm 4 which, in its turn, presses the actuating member 23 of the microswitch into the operating position shown in FIG. 3, in which the safety loop is closed. In normal operation, the movement on the pressure rod takes place between the initial position according to FIG. 1 and the operating position according to FIG. 3.
  • the pressure plate When in the operating position according to FIG. 3 and an emergency situation arises, the pressure plate can either be released or be pressed in further. In the latter case, an increased pressure is required for the ball 43 to pass the shoulder 37 between the deeper portion 36 and the shallower portion 38 on the pressure rod. This increased pressure is determined by the spring 42.
  • the lever arm 4 When the ball has arrived on the shallower portion 38 of the pressure rod, the lever arm 4 is disengaged from the pressure rod and the microswitch can return to its open position while being influenced by the return spring 24, while continuing the pressing of the pressure rod until the rod has reached its second end position according to FIG. 4. Also in this end position, the safety loop is thus open.. To get from the second end position according to FIG. 4 to the first end position (initial position) according to FIG.
  • the pressure plate 32 is released and the switch resumes the initial position with the aid of the spring 33.
  • the microswitch 2 is not influenced, and the safety loop is thus open during the whole return movement.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Robotics (AREA)
  • Push-Button Switches (AREA)
  • Mechanisms For Operating Contacts (AREA)
  • Mechanical Control Devices (AREA)
US08/211,866 1991-11-01 1992-10-14 Safety switch for an industrial machine Expired - Lifetime US5444203A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE9103211A SE470428B (sv) 1991-11-01 1991-11-01 Säkerhetsbrytare för industrimaskin
SE9103211 1991-11-01
PCT/SE1992/000720 WO1993009377A1 (en) 1991-11-01 1992-10-14 Safety switch for an industrial machine

Publications (1)

Publication Number Publication Date
US5444203A true US5444203A (en) 1995-08-22

Family

ID=20384190

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/211,866 Expired - Lifetime US5444203A (en) 1991-11-01 1992-10-14 Safety switch for an industrial machine

Country Status (7)

Country Link
US (1) US5444203A (ja)
EP (1) EP0610389B1 (ja)
JP (1) JP3418394B2 (ja)
DE (1) DE69228001T2 (ja)
ES (1) ES2128360T3 (ja)
SE (1) SE470428B (ja)
WO (1) WO1993009377A1 (ja)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0927611A1 (en) * 1997-04-21 1999-07-07 Fanuc Ltd Emergengy stop switching mechanism for robot and teaching control panel provided with same
US20050265506A1 (en) * 1994-10-06 2005-12-01 Mosaid Technologies, Inc. Delay locked loop implementation in a synchronous dynamic random access memory
US20060201684A1 (en) * 2005-03-10 2006-09-14 Throttle Control Tech Inc. Throttle limiting control box for snubbing units in conjunction with service or drilling rigs
EP1772879A2 (en) 2005-10-06 2007-04-11 Abb As Control system and teach pendant for an industrial robot
US20070164696A1 (en) * 2005-12-21 2007-07-19 Abb As Control system and teach pendant for an industrial robot
US20080156910A1 (en) * 2006-12-27 2008-07-03 Michilin Prosperity Co., Ltd. Emergency stop switch of shredder
USRE40552E1 (en) 1990-04-06 2008-10-28 Mosaid Technologies, Inc. Dynamic random access memory using imperfect isolating transistors
WO2012143053A1 (en) 2011-04-21 2012-10-26 Abb Technology Ag A hand-held terminal unit, an industrial robot system and a method for controlling an industrial robot
US8939219B2 (en) 2011-05-05 2015-01-27 Snubco Manufacturing Inc. System and method for monitoring and controlling snubbing slips
US20210399614A1 (en) * 2018-11-09 2021-12-23 Linak A/S Emergency stop

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5547675A (en) * 1989-09-13 1996-08-20 Exxon Chemical Patents Inc. Modified monocyclopentadienyl transition metal/alumoxane catalyst system for polymerization of olefins
GB2316458A (en) * 1996-08-23 1998-02-25 Electrolux Outdoor Prod Ltd A switch actuating mechanism having lost motion means
AT410710B (de) * 2001-07-31 2003-07-25 Keba Ag Sicherheitsschalteinrichtung für elektrisch gesteuerte maschinen

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2616009A (en) * 1950-08-10 1952-10-28 Exhibit Supply Co Mechanism for operating a momentary switch for an electric circuit
US2919333A (en) * 1957-11-04 1959-12-29 Harold W Scholin Electrical switch mechanism
US3118206A (en) * 1961-05-15 1964-01-21 Barnett Sonja Pin type fastening devices
US3384725A (en) * 1966-11-23 1968-05-21 Sperry Rand Corp Switch actuating mechanism (momentary type) for pin-plunger type electrical switch
US3674970A (en) * 1970-10-23 1972-07-04 Cherry Electrical Prod Panel-mounted switch
US4450331A (en) * 1983-06-08 1984-05-22 Amp Incorporated Key switch assembly having momentary closed interval

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE458183B (sv) * 1986-06-24 1989-03-06 Inst Verkstadstek Forsk Ivf Haalldon

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2616009A (en) * 1950-08-10 1952-10-28 Exhibit Supply Co Mechanism for operating a momentary switch for an electric circuit
US2919333A (en) * 1957-11-04 1959-12-29 Harold W Scholin Electrical switch mechanism
US3118206A (en) * 1961-05-15 1964-01-21 Barnett Sonja Pin type fastening devices
US3384725A (en) * 1966-11-23 1968-05-21 Sperry Rand Corp Switch actuating mechanism (momentary type) for pin-plunger type electrical switch
US3674970A (en) * 1970-10-23 1972-07-04 Cherry Electrical Prod Panel-mounted switch
US4450331A (en) * 1983-06-08 1984-05-22 Amp Incorporated Key switch assembly having momentary closed interval

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE40552E1 (en) 1990-04-06 2008-10-28 Mosaid Technologies, Inc. Dynamic random access memory using imperfect isolating transistors
US20050265506A1 (en) * 1994-10-06 2005-12-01 Mosaid Technologies, Inc. Delay locked loop implementation in a synchronous dynamic random access memory
US8638638B2 (en) 1994-10-06 2014-01-28 Mosaid Technologies Incorporated Delay locked loop implementation in a synchronous dynamic random access memory
US8369182B2 (en) 1994-10-06 2013-02-05 Mosaid Technologies Incorporated Delay locked loop implementation in a synchronous dynamic random access memory
US7599246B2 (en) 1994-10-06 2009-10-06 Mosaid Technologies, Inc. Delay locked loop implementation in a synchronous dynamic random access memory
EP0927611A4 (en) * 1997-04-21 2001-03-28 Fanuc Ltd EMERGENCY ALARM CIRCUIT FOR ROBOTS AND A LEARNING CONTROL PANEL THEREFORE
EP0927611A1 (en) * 1997-04-21 1999-07-07 Fanuc Ltd Emergengy stop switching mechanism for robot and teaching control panel provided with same
US20060201684A1 (en) * 2005-03-10 2006-09-14 Throttle Control Tech Inc. Throttle limiting control box for snubbing units in conjunction with service or drilling rigs
US7487839B2 (en) 2005-03-10 2009-02-10 Throttle Control Tech Inc. System for controlling the vertical movement of pipe through a stripping ram in conjunction with service or drilling rigs
US20080255704A1 (en) * 2005-10-06 2008-10-16 Knut Braut Control System and Teach Pendant For An Industrial Robot
EP1772879A2 (en) 2005-10-06 2007-04-11 Abb As Control system and teach pendant for an industrial robot
US8010234B2 (en) 2005-12-21 2011-08-30 Abb As Control system and teach pendant for an industrial robot
US20070164696A1 (en) * 2005-12-21 2007-07-19 Abb As Control system and teach pendant for an industrial robot
US7414212B2 (en) * 2006-12-27 2008-08-19 Michilin Prosperity Co., Ltd. Emergency stop switch of shredder
US20080156910A1 (en) * 2006-12-27 2008-07-03 Michilin Prosperity Co., Ltd. Emergency stop switch of shredder
WO2012143053A1 (en) 2011-04-21 2012-10-26 Abb Technology Ag A hand-held terminal unit, an industrial robot system and a method for controlling an industrial robot
US8939219B2 (en) 2011-05-05 2015-01-27 Snubco Manufacturing Inc. System and method for monitoring and controlling snubbing slips
US20210399614A1 (en) * 2018-11-09 2021-12-23 Linak A/S Emergency stop
US11888358B2 (en) * 2018-11-09 2024-01-30 Linak A/S Emergency stop activating a circuit breaker

Also Published As

Publication number Publication date
JP3418394B2 (ja) 2003-06-23
EP0610389B1 (en) 1998-12-23
SE9103211D0 (sv) 1991-11-01
SE470428B (sv) 1994-02-21
DE69228001T2 (de) 1999-08-19
SE9103211L (sv) 1993-05-02
DE69228001D1 (de) 1999-02-04
WO1993009377A1 (en) 1993-05-13
ES2128360T3 (es) 1999-05-16
JPH07500945A (ja) 1995-01-26
EP0610389A1 (en) 1994-08-17

Similar Documents

Publication Publication Date Title
US5444203A (en) Safety switch for an industrial machine
EP0483926B1 (en) Trailer coupling with friction damper
US5860488A (en) Safety lever apparatus and a method of using the same
WO2001048773A1 (fr) Actionneur de commutateur de securite
GB2377005A (en) Arcuate track joystick assembly
DE102007018891A1 (de) Schaltvorrichtung
US5161679A (en) Electrical trigger switch with safety features
DE102009012167A1 (de) Betätigungsvorrichtung für ein Fahrzeug
DE10297207B4 (de) Sicherheitsschalteinrichtung für elektrisch gesteuerte Maschinen
US4229993A (en) Actuating device
US5499548A (en) Manually operated actuating device
EP1365429B1 (en) Enable switch
US5133222A (en) Operating mechanism for vehicles with automatic transmission
EP1528583B1 (en) Key-top
US4309582A (en) Push button switch for a controller
AT390154B (de) Sicherungsautomat mit fernsteuerung eines unterbrecherkontaktes
EP1440258A1 (de) Vorrichtung für das erzeugen von schaltkräften
US4675485A (en) Handgrip having dead-man-switch action for construction equipment
WO1999017960A1 (de) Elektrischer hebelschalter
US4433224A (en) Actuator mechanism with enhanced tactile characteristics
CA2009059A1 (en) Control mechanism for an on-off switch
DE102004036844B4 (de) Wippschalter
US3491867A (en) Two-handed safety control
DE19731345A1 (de) Vorrichtung zur drahtlosen Steuerung
RU1838144C (ru) Исполнительный механизм механического пресса

Legal Events

Date Code Title Description
AS Assignment

Owner name: ASEA BROWN BOVERI AB, SWEDEN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GUNNARSSON, SVEN-ERIC;REEL/FRAME:007071/0734

Effective date: 19940411

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12